Yesterday, November 7th, BioWare celebrated "N7 Day" by holding a special livestream and Mass Effect 3 multiplayer sessions. But that's not all they celebrated. As Joystiq points out, several of their developers took the celebration to Twitter, complete with teaser images of the next Mass Effect game.
Throughout this slideshow I'll give a few words on each picture, and also include the corresponding tweet to the image above, with the first as follows:
— Michael Gamble (@GambleMike) November 7, 2013
It appears he's testing out the gameplay on a PC with an Xbox 360 controller. Not much can be gleamed from this image due to the sunlight on the monitor, but it looks like there is a portal of some sort?